Recent years, there has been a full-fledged proliferation, in households, of home theater systems that combine a set top box (hereafter called STB) which receives a digital broadcast or a cable television (hereafter called CATV) broadcast, a television, a speaker, and a Digital Versatile Disk (DVD) player. With these devices, it is possible to implement the reproduction of multi-channel audio, for example 5.1 channel audio, by setting the respective devices with the use of a remote control (see Non-Patent Reference 1).
There is proposed a technique (device linkage apparatus) for switching between outputting audio only from a television reception apparatus and outputting the audio from a speaker connected to an amplifier, in linkage with the ON/OFF operation of the power switch of the amplifier (see for example Patent Reference 1).
For example, the device linkage apparatus in the aforementioned Patent Reference 1 is included in an AV amplifier that is capable of configuring a surround system by being combined with a television reception apparatus. In other words, the device linkage apparatus in the aforementioned Patent Reference 1 can perform switching between the use of the surround system and the individual use of the television reception apparatus.
FIG. 1 shows a block diagram of the AV amplifier in the aforementioned Patent Reference 1.
With such an device linkage apparatus in an AV amplifier 40, when a power switch 41 of the AV amplifier 40 is turned ON during use of the surround system, a change-over switch 50 is switched to a center audio amplification circuit 48. As a result, an audio signal supplied to an audio input terminal 43 from a reproduction device such as a Video Tape Recorder (VTR) or a Laser Disc (LD), for example, or a television reception apparatus connected to the AV amplifier 40 is supplied to surrounding speakers, via a DSP 45 and through an audio output terminal 49.
With such a device linkage apparatus in the AV amplifier 40, when the power switch 41 of the AV amplifier 40 is turned OFF during independent use of the television reception apparatus, the change-over switch 50 is switched to a television audio input terminal 51. As a result, television audio processed in the amplification circuit of the television reception apparatus is supplied to a speaker of the television reception apparatus, via the AV amplifier 40.    Non-Patent Reference 1: High Definition Multimedia Interface specification Version 1.2    Patent Reference 1: Japanese Unexamined Patent Application Publication No. 5-153520